17,817 research outputs found

    A computer code for calculations in the algebraic collective model of the atomic nucleus

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    A Maple code is presented for algebraic collective model (ACM) calculations. The ACM is an algebraic version of the Bohr model of the atomic nucleus, in which all required matrix elements are derived by exploiting the model's SU(1,1) x SO(5) dynamical group. This paper reviews the mathematical formulation of the ACM, and serves as a manual for the code. The code enables a wide range of model Hamiltonians to be analysed. This range includes essentially all Hamiltonians that are rational functions of the model's quadrupole moments qMq_M and are at most quadratic in the corresponding conjugate momenta πN\pi_N (2M,N2-2\le M,N\le 2). The code makes use of expressions for matrix elements derived elsewhere and newly derived matrix elements of the operators [πqπ]0[\pi\otimes q \otimes\pi]_0 and [ππ]LM[\pi\otimes\pi]_{LM}. The code is made efficient by use of an analytical expression for the needed SO(5)-reduced matrix elements, and use of SO(5)\,\supset\,SO(3) Clebsch-Gordan coefficients obtained from precomputed data files provided with the code.Comment: REVTEX4. v2: Minor improvements and corrections. v3: Introduction rewritten, references added, Appendix B.4 added illustrating efficiencies obtained using modified basis, Appendix E added summarising computer implementation, and other more minor improvements. 43 pages. Manuscript and program to be published in Computer Physics Communications (2016

    Coherent state triplets and their inner products

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    It is shown that if H is a Hilbert space for a representation of a group G, then there are triplets of spaces F_H, H, F^H, in which F^H is a space of coherent state or vector coherent state wave functions and F_H is its dual relative to a conveniently defined measure. It is shown also that there is a sequence of maps F_H -> H -> F^H which facilitates the construction of the corresponding inner products. After completion if necessary, the F_H, H, and F^H, become isomorphic Hilbert spaces. It is shown that the inner product for H is often easier to evaluate in F_H than F^H. Thus, we obtain integral expressions for the inner products of coherent state and vector coherent state representations. These expressions are equivalent to the algebraic expressions of K-matrix theory, but they are frequently more efficient to apply. The construction is illustrated by many examples.Comment: 33 pages, RevTex (Latex2.09) This paper is withdrawn because it contained errors that are being correcte

    Construction of SU(3) irreps in canonical SO(3)-coupled bases

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    Alternative canonical methods for defining canonical SO(3)-coupled bases for SU(3) irreps are considered and compared. It is shown that a basis that diagonalizes a particular linear combination of SO(3) invariants in the SU(3) universal enveloping algebra gives basis states that have good KK quantum numbers in the asymptotic rotor-model limit.Comment: no figure

    Decision Making Towards Maternal Health Services in Central Java, Indonesia

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    Background: Indonesia has always been struggling with maternal health issue even after the Millennium Development Goals (MDGs) programs were done. Prior research findings identified many factors which influenced maternal health status in developing countries such Indonesia and even though various efforts had been made, the impact of the transformation of maternal health behavior was minimal.Purpose: This study aimed to seek an understanding of the factors influencing decisions towards maternal health services.Methods: A case study with a single case embedded design was employed. Interviews and Focus Group Discussions (FGDs) were held to collect data from 3 health workers and 40 maternal women in a sub-district in Central Java, Indonesia.Results: Interviews with the village midwives as the main health providers in the Getasan sub-district concluded that there were several factors influencing the women\u27s decisions towards maternal services. The factors were options to have services with other health workers outside the area, and shaman services as alternative care and family influencing maternal health behaviors. The analysis of the FGDs also supported the village midwives\u27 statements that in spite of their awareness towards the available maternal health services, the existence of shamans and traditional beliefs strongly affected their decision.Conclusion: The findings in this study showed that cultural issues prevented the maximum maternal health status in Getasan sub-district. This study recommends Puskesmas (Primary Health Care) as the first level of health institutions in Indonesia to support the village midwives\u27 roles within their target area

    Weak Gravitational Flexion

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    Flexion is the significant third-order weak gravitational lensing effect responsible for the weakly skewed and arc-like appearance of lensed galaxies. Here we demonstrate how flexion measurements can be used to measure galaxy halo density profiles and large-scale structure on non-linear scales, via galaxy-galaxy lensing, dark matter mapping and cosmic flexion correlation functions. We describe the origin of gravitational flexion, and discuss its four components, two of which are first described here. We also introduce an efficient complex formalism for all orders of lensing distortion. We proceed to examine the flexion predictions for galaxy-galaxy lensing, examining isothermal sphere and Navarro, Frenk & White (NFW) profiles and both circularly symmetric and elliptical cases. We show that in combination with shear we can precisely measure galaxy masses and NFW halo concentrations. We also show how flexion measurements can be used to reconstruct mass maps in 2-D projection on the sky, and in 3-D in combination with redshift data. Finally, we examine the predictions for cosmic flexion, including convergence-flexion cross-correlations, and find that the signal is an effective probe of structure on non-linear scales.Comment: 17 pages, including 12 figures, submitted to MNRA

    Use of Standardized Assessments and Online Resources in Stroke Rehabilitation

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    Background: The extent to which movement-related standardized assessments and online resources are used in stroke rehabilitation is unclear in the United States. Method: The researchers used a cross-sectional descriptive survey that examined (a) therapists use of movement-related standardized assessments, (b) factors influencing learning of new assessments, and (c) use of frequency of online resources by occupational therapists and physical therapists in the United States. Results: Of 151 respondents (46.4% occupational therapists, 53.6% physical therapists), the most frequently used movement-related assessments by occupational and physical therapists were the Berg and Fugl-Meyer Assessment, respectively. More physical therapists use motor-related standardized assessments regularly than occupational therapists, and physical therapists showed more consensus among standardized assessments. Both professions cited quality of patient care for motivating them to integrate outcome measures into practice. Most therapists in stroke rehabilitation used online resources to access movement-related standardized assessment content at least 25% of the time. The Rehabilitation Measures Database was the most frequently used website. Conclusion: Both occupational and physical therapists use online resources for movement-related standardized assessments on a regular basis. However, occupational therapists do not use standardized assessments as frequently as physical therapists. A systematic study of factors that impact the integration of standardized assessments is needed to further identify barriers and inform clinical practice change

    Preparation of Dicke States in an Ion Chain

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    We have investigated theoretically and experimentally a method for preparing Dicke states in trapped atomic ions. We consider a linear chain of NN ion qubits that is prepared in a particular Fock state of motion, m>|m>. The mm phonons are removed by applying a laser pulse globally to the NN qubits, and converting the motional excitation to mm flipped spins. The global nature of this pulse ensures that the mm flipped spins are shared by all the target ions in a state that is a close approximation to the Dicke state \D{N}{m}. We calculate numerically the fidelity limits of the protocol and find small deviations from the ideal state for m=1m = 1 and m=2m = 2. We have demonstrated the basic features of this protocol by preparing the state \D{2}{1} in two 25^{25}Mg+^+ target ions trapped simultaneously with an 27^{27}Al+^+ ancillary ion.Comment: 5 pages, 2 figure

    Preliminary design of a Primary Loop Pump Assembly (PLPA), using electromagnetic pumps

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    A preliminary design study of flight-type dc conduction-permanent magnetic, ac helical induction, and ac linear induction pumps for circulating 883 K (1130 F) NaK at 9.1 kg/sec (20 lb/sec) is described. Various electromagnetic pump geometrics are evaluated against hydraulic performance, and the effects of multiple windings and numbers of pumps per assembly on overall reliability were determined. The methods used in the electrical-hydraulic, stress, and thermal analysis are discussed, and the high temperature electrical materials selected for the application are listed
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